Water bottles and similar hydration systems are popular, particularly among outdoor athletes—for example, by persons engaged in hiking, biking, skating, etc. Hydration systems are convenient for rehydrating a person who has lost body fluids as a result of heat, physical exertion, arid environment, and/or the passage of time. There are two general types of hydration systems—(1) hard or rigid/semirigid container systems, and (2) soft or flexible bladder systems.
A hard container system includes a hard or semirigid container that is made from plastic, metal, glass, or another material that holds its shape when the container is empty. The container typically includes a removable lid, providing access to the contents of the container. Examples of such containers include, but are not limited to, NALGENE® brand bottles, sports cycle bottles, canteens, and glass bottles. Hard container systems provide many advantages. For example, hard containers can easily be cleaned and can hold a number of different liquids, including water. Because the container is generally rigid or semirigid, it is sturdy and difficult to puncture. Moreover, the container typically retains its shape in a backpack, even when other items are placed on top of the container. A rigid or semirigid container system can be transported separate from or away from the user—for example, in a water carrier on a bicycle. Alternatively, a hard container system can be mounted in a wearable carrier, allowing the weight of the liquid to be efficiently transferred to the user's hips.
Hard container systems, however, often require that the container be physically removed from a carrier or other support mechanism that holds the container. This may require the user to stop doing whatever physical activity is being performed or to substantially interrupt such activity in order to remove the container from its carrier or holder so that the user can rehydrate. Most rigid containers are carried in this fashion.
Another disadvantage of hard container systems is that for the liquid to be efficiently removed from a rigid or semirigid container, the container must be vented to permit air to enter the container in order to replace the volume of liquid being removed from the container. Without such a vent, the removal of the liquid will generally cause a partial vacuum to form in the container, impeding or completely preventing the flow of the liquid out of the container.
In many applications it is undesirable to have a vent that is always open. If the vent remains open during exposure to harsh environmental conditions, the vent could allow dirt to enter the container, resulting in contamination of the liquid. Dirt can also obstruct the vent, thereby rendering the vent inoperable. Therefore, the user may be required to open a vent prior to consuming the contents of the container, further interrupting the user's activities.
Systems have been proposed that incorporate automatically operable mechanical vents, e.g., check valves, that require a pressure differential that must be overcome to open the vent. These automatic vents, however, require additional pressure differential to extract the fluid and therefore add resistance to the overall system. In some rigid containers an extra-wide drinking opening is provided, such that the liquid egress and vent air can simultaneously pass through the same opening. Such containers however, can be difficult to drink from without spilling the contents.
To avoid some of the disadvantages discussed above, hard container hydration systems are sometimes equipped with an elongate, flexible drinking tube that extends from the container to the user's mouth. The tube may be quite long, and the elevation difference from the top of the container to the user's end of the tube (that may include a mouth dispenser) can often be several feet. This requires the user to suck the liquid through the length of the tube at each use. Some systems utilize a check valve to prevent the liquid from returning to the container, i.e., whereby a volume of liquid remains in the tube. Alternatively, some systems use motorized or manual pumps to force liquid through the liquid tube, while other systems require complicated valves either in the liquid tube or mouth dispenser.
Check valves and unidirectional valves have a set pressure differential that must be overcome for the valve to operate properly. For example, a check valve may use spring tension or the resilient nature of a plastic or rubber material to urge the valve to a closed position. This tension is typically preset so the pressure required to open the valve remains substantially constant. Similarly, if a liquid tube or vent contains an in-line check valve, the force to open the valve remains constant regardless of all other conditions in the system. Generally speaking, check valves are expensive to manufacture, degrade over time, malfunction when dirty, freeze easily, and allow fluid to flow in a single direction.
Moreover, some hard container systems with drinking tubes requiring the bottle to be inverted so that gravity can help pull air into the container when the user ceases to suck liquid from the drinking tube, are known in the art.
Soft bladder container systems overcome many of the disadvantages of hard container systems. A soft bladder container system typically includes a pliable liquid container or bladder that provides a liquid reservoir. The bladder is easily compressed, folded, or deformed. Examples of this type of system include, but are not limited to, the CAMELBAK® brand system, the PLATYPUS® brand system, bota bags, and collapsible water pails. The bladder or pliable container, however, generally requires some type of support when the container is filled with a liquid—for example, a backpack-type assembly. A tube is typically provided to the container, allowing the user to draw water to from the reservoir of the soft bladder system. An advantage of such soft bladder systems is that the user can rehydrate without stopping an activity. Because the soft bladder container is pliable, it can collapse as liquid is removed, obviating the need for a vent, and it is easier to draw liquid from the bladder because no check valve is required. In conventional, soft bladder container systems, the soft bladder must be operated with its tube at the container's lowest point in order for the bladder to be fully evacuated during use.
A disadvantage of soft bladder systems is that they are susceptible to punctures and leaks. While positioned upside down and supported inside a carrier pack, a leak can drain the bladder of liquid into vital gear, such as a sleeping bag or clothing. The flexible materials that are used to manufacture the soft bladder hydration systems are selected to withstand water but may deteriorate or absorb nonwater constituents present in other liquids. A soft bladder type of system is often transported on the back of the user, which may increase the risk of back fatigue and back injury. The construction of a soft bladder hydration system typically causes water to flow from the liquid dispenser when the bladder becomes compressed during use. In addition, a soft container is extremely difficult to clean. Many manufacturers of soft bladder hydration systems often offer secondary products such as patch kits, cleaning brushes, cleaning holders, and extensive cleaning chemicals for their systems.
There remains a need, therefore, for a hydration system that provides the advantages of ruggedness of rigid container systems while also providing the ease of use and availability of soft bladder container systems.